食品安全问题一直是社会和广大群众关注的焦点问题, 食品安全现状较为严峻, 因此实现食品中有害物质的快速检测具有重要的实际意义。 合成色素是一种常见的食品添加剂, 然而合成色素的超标添加和非法添加依旧是食品安全中的重要问题之一, 极大地危害人民群众的身体健康和食品工业的健康发展。 常见的合成色素检测方法, 均存在耗时长、 费用高等缺点, 不适应于合成色素的实时监测和快速筛查。 为克服传统方法的缺点, 提出利用表面增强拉曼光谱检测技术对合成色素进行检测, 该方法具有检测速度快、 检测灵敏度高等优点, 能够达到现场实时检测的目的。 此外, 由于拉曼检测方法往往依赖于复杂的样品前处理操作, 而常见的固相萃取技术一般依赖于人工操作, 过程复杂且耗时较长, 严重影响食品快速检测效率。 因此, 开发了一种全自动固相萃取装置, 通过设计嵌入式硬件电路系统及其软件, 精确控制蠕动泵流速和多路阀门开关实现了活化、 上样、 淋洗、 洗脱四个步骤的全自动操作和参数控制, 从而达到食品样品的全自动快速固相萃取。 在实验部分, 配制不同专利蓝V浓度的果汁饮料, 然后利用该装置对果汁中的专利蓝V进行前处理, 对萃取柱填料和萃取中各个步骤的时间和试剂进行了合理的选择, 利用表面增强拉曼光谱检测技术成功地检测了合成色素中的专利蓝V。 实验结果表明, 所研制的自动固相萃取装置对比传统手工萃取, 每个样品节省了近一半的萃取时间(10 min降为5 min)且能够同时处理5个样品, 萃取时间稳定不易受人为因素影响, 从而极大地提高了萃取效率和稳定性。 此外, 通过自动萃取获得的样品, 对比手工萃取操作, 因其受外界干扰相对较小, 能够得到更强的拉曼光谱信号(约增强50%), 获得了满意的萃取效果。 对不同浓度的专利蓝V样品的结果显示, 该方法能够实现检出质量浓度在0.5 mg·L^-1水平, 可有效满足现场监测需求。 具有快速、 方便、 灵敏度高等特点。

Food safety has been the focus problem concerned by the society and the general public whose current state is serious, so it is of great practical significance to realize the rapid detection of harmful substances in food. Synthetic pigment is a common food additive whose excessive and illegal addition is still one of the important problems in food safety, which greatly endangers the health of the people and the healthy development of food industry. Common synthetic pigment detection methods have the disadvantages of long time consumption and high cost, which are not suitable for real-time monitoring and rapid screening of synthetic pigments. In order to overcome the shortcomings of the traditional methods, this paper proposes the use of surface-enhanced Raman spectroscopy to detect synthetic pigments. This method has the advantages of fast detection speed and high detection sensitivity, and can achieve real-time detection in the field. In addition, since Raman detection methods often rely on complex sample preparation operations, and common solid phase extraction techniques rely on manual operations, which are complicated and time consuming, and seriously restrict the rapid detection efficiency of food. Therefore, in this paper, the automatic solid phase extraction device, including mechanical, electrical and software modules, was designed, and by precise control of peristaltic pump flow rate and multi-way valve switch in four steps of activation, loading, rinsing and elution, the device realized the automatic fast solid phase extraction of food samples. In the experimental part, the juice drink with different patent blue V concentrations was prepared, and then the device was used to pre-treat the patent blue V in the juice, in which the extraction column packing and the time and parameters of each step were rationally selected, and then the Raman spectra of patented blue V were successfully detected. The experimental results showed that, compared with traditional manual extraction, the automatic solid phase extraction device has saved nearly half of the extraction time (10 minutes down to 5 minutes) and can process five samples at the same time. The extraction time was not easy to be affected by human factors which significantly improved the efficiency and stability of the sample pretreatment. Meanwhile, because it was relatively less interfered by the external environment, a stronger Raman spectral signal (about 50% enhancement) could be obtained, so the extraction effect was also satisfactory. The results of different concentrations of patented blue V samples show that the method can achieve a detection concentration of 0.5 mg·L^-1, which can effectively meet the needs of on-site monitoring, and is characterized by fast, convenient and high sensitivity.